The present invention relates to an edge stiffener or margin reinforcement for the openings of plastic bags, the edges of plastic sheets, and the like.
A device for this general purpose is known from U.S. Pat. No. 4,379,519 in which a flexible plastic band is folded in U-form, placed over the edge of the opening of a bag and held there with clamps. Folding of such a plastic band is relatively difficult. Securing of the band by means of clamps is relatively expensive. Further, it is not possible to change the configuration of the opening of the bag to any desired configuration after the stiffener has been attached.